Polyalkylene oxide-rubber block copolymers and methods for making the same

Abstract

In one aspect, the disclosure relates to a block copolymer comprising a first block derived from an alkene and a second block derived from an epoxide. In another aspect, the block copolymer has the structure wherein X is selected from: or any combination thereof; wherein R 1 is selected from H or a C1-C4 aliphatic hydrocarbon chain, wherein R 2 and R 3 are individually selected from H or methyl; wherein n is from about 1800 to about 20,000; and wherein m is from 4 to 2300. Also disclosed herein are rubber compositions including the disclosed block copolymers, tires including the rubber compositions, and methods of making the block copolymers.

What is claimed is: 
     
         1 . A block copolymer comprising a first block derived from an alkene and a second block derived from an epoxide. 
     
     
         2 . The block copolymer of  claim 1 , wherein the alkene comprises styrene, butadiene, isoprene, or any combination thereof. 
     
     
         3 . The block copolymer of  claim 1 , wherein the second block comprises polypropylene oxide units or polybutylene oxide units. 
     
     
         4 . The block copolymer of  claim 1 , wherein the block copolymer has the structure: 
       
         
           
           
               
               
           
         
         wherein X is selected from: 
       
       
         
           
           
               
               
           
         
       
       or any combination thereof;
 wherein R 1  is selected from H or a C1-C4 aliphatic hydrocarbon chain, 
 wherein R 2  and R 3  are individually selected from H or methyl; 
 wherein n is from about 1800 to about 20,000; and 
 wherein m is from 4 to 2300. 
 
     
     
         5 . A rubber composition comprising the block copolymer of  claim 1  and at least one filler. 
     
     
         6 . A tire comprising the rubber composition of  claim 5 . 
     
     
         7 . A method for making a block copolymer comprising a first block derived from an alkene and a second block derived from an epoxide, the method comprising:
 (a) polymerizing an alkene to produce a polymerized alkene; and   (b) polymerizing an epoxide in the presence of the polymerized alkene to produce the block copolymer.   
     
     
         8 . The method of  claim 7 , wherein polymerizing the alkene in step (a) comprises mixing the alkene with an initiator and a multidentate ligand in a first solvent. 
     
     
         9 . The method of  claim 8 , wherein the initiator comprises n-butyllithium, s-butyllithium, t-butyllithium, or any combination thereof. 
     
     
         10 . The method of any one of  claim 8 , wherein the multidentate ligand comprises tetramethylethylenediamine (TMEDA), ditetrahydrofurylpropane (DTP), or any combination thereof. 
     
     
         11 . The method of  claim 7 , wherein the alkene comprises butadiene, isoprene, styrene, or any combination thereof. 
     
     
         12 . The method of  claim 7 , further comprising adding an organoaluminum compound during step (b). 
     
     
         13 . The method of  claim 12 , wherein the organoaluminum compound comprises triisobutylaluminum. 
     
     
         14 . The method of  claim 7 , wherein the block copolymer is precipitated from a third solvent, pan dried, drum dried, or stripped to recover the block copolymer. 
     
     
         15 . The block copolymer of  claim 1 , wherein the first block comprises polybutadiene, polyisoprene, or styrene butadiene rubber. 
     
     
         16 . The block copolymer of  claim 1 , wherein the block copolymer has a glass transition temperature (T g ) of from about −90° C. to about −5° C. 
     
     
         17 . The block copolymer of  claim 1 , wherein the first block has a molecular weight of from about 2 kDa to about 1,000,000 kDa. 
     
     
         18 . The block copolymer of  claim 1 , wherein the block copolymer comprises from about 0.5 wt % to about 10 wt % of the second block. 
     
     
         19 . The block copolymer of  claim 1 , wherein the second block has a molecular weight of from about 0.2 kDa to about 2 kDa. 
     
     
         20 . The rubber composition of  claim 5 , wherein the at least one filler comprises silica, carbon black, or any combination thereof.